A group at Osaka University revealed that fasting activates adipose tissue autophagy (the mechanism of decomposition of unwanted structures in cells), which induces fat accumulation and ketone body production in the liver. ..A previous study by the group found that autophagy was excessive in aged adipose tissue and caused fatty liver, which now reveals a common mechanism between fasting and aging.
First, in this study, we found that autophagy-suppressing factors were inactivated in the adipose tissue of mice during fasting, and found that fasting induces autophagy.It was also found that the degradation of the inhibitor Rubicon by autophagy further promotes autophagy and degrades proteins involved in fat accumulation.This impedes the fat storage of adipocytes, and the released fat migrates to the liver and accumulates (fatty liver).
It has long been known that when an individual is exposed to starvation, adipose tissue is reduced and instead fat is taken up by the liver and used for the production of ketone bodies as an emergency nutrition. The mechanism was identified for the first time.On the other hand, it was also clarified at the same time that the phenomenon in which autophagy activity is increased in aged adipocytes and contributes to fatty liver is a mechanism that originally exists for the production of ketone bodies required at the time of fasting.That is, it is suggested that aging of adipocytes may be a state in which the mechanism of fasting occurs even at normal times.
Why does aging work the same mechanism as during fasting?If this mystery becomes clear from this research, it is expected that the understanding of the pathophysiology of adipocyte aging and lifestyle-related diseases associated with aging will advance.
Paper information:[Autophagy] Loss of Rubicon in adipocytes mediates the upregulation of autophagy to promote the fasting response
